Seasat

A NASA/JPL (Jet Propulsion Laboratory) satellite that carried
out the first remote sensing of Earth's oceans using synthetic
aperture radar (SAR). The mission ended on Oct. 10, 1978, due to a failure
of the vehicle's electric power system. Although only about 42 hours of
real-time data was received, the mission proved the feasibility of using
microwave sensors to monitor ocean conditions, and laid the groundwork for
future SAR missions. As well as the SAR, Seasat's payload included a scatterometer
to measure wind speed and direction, a multichannel microwave radiometer
to measure surface wind speed, ocean surface temperature, atmospheric water
vapor content, rain rate, and ice coverage, and a visible and infrared radiometer
to identify cloud, land and water features, and provide ocean thermal images.